1. Field of the Invention
The present invention relates to an image forming apparatus such as the laser beam printer and the copying machine.
2. Description of the Related Art
In the case of the laser beam printer recently developed, such laser beam as corresponds to image signals is lead onto the pre-charged surface of the photosensitive drum to form an electrostatic latent image thereon. This latent image is developed by toner. A toner image is thus formed on the photosensitive drum. This toner image is transferred onto a sheet of paper at the transfer section.
When the efficiency of forming images successively is to be enhanced in the case of this laser beam printer, it is important how the interval of forming images one after another or the timing of supplying paper sheets one after another is set. Conventionally, the supply of a next paper sheet to the transfer section has already started before its previous paper sheet is discharged from the printer. When the paper sheets supply is switched to another paper sheets supply system in the course of the continuous images forming operation, however, a new paper sheet is supplied after the previous paper sheet is discharged from the printer. It is therefore impossible to supply paper sheets at an optimum quick timing from the switched paper sheets supply system. This causes the images forming efficiency to become low.